Figure 1.

Domain organizations and overall structures of N46 bound PKG Iα and PKA Cα. A, the domain organizations of PKG Iα and PKA Cα. The catalytic domains used for crystallization are shaded in orange and labeled with the corresponding residue numbers. Phosphorylated residues are indicated (PKG Iα T517 and PKA Cα S139/T197/S338). B and C, overall structures of the PKG Iα C–Ν46 (B) and PKA Cα–N46 (C) complexes. The N-and C termini are labeled with the corresponding residue numbers. The structures are rendered as cartoons, with N46 shown as sticks. The small and large lobes are colored gray and tan, respectively. Atoms in N46 are colored as follows: carbons, yellow; oxygen, red; nitrogen, blue; fluorine, cyan. Enlarged views show Fo-Fc omit maps of N46 (contoured at 3.0 σ level).